Usually the simple things are the root cause so make sure you have rebooted PC and restarted your internet connection (e.g. reboot router). Also try a different PC in your house if you have one - just to see.
Then experiment with turning off firewall and anti virus (only for a one time connection just to see if those are blocking your access - Make sure you remember to restart these!!)
If none of this works-
Next try a tracert from your PC.
(funny enough 'tracert is short for 'trace route')

Here's how if you're not familiar with tracert -
Go to Start - Run (if you have that in the start menu)
- otherwise -
Go to Start - All Programs - Accessories - Command Prompt
Type
tracert www.simviation.comRight Click 'Select All' when the progress has reached 'pccw'
This copies the content to your clipboard ready for pasting here.
The tracert will show any problem nodes between your PC and our server.
Simplicity is the ultimate sophistication. – Leonardo da Vinci